Fish Are Starving For Rain

You can`t really see much wrong with the Cook County Forest Preserve lakes and ponds.

Sure, the banks are showing. The water is down and the fish are not where they used to be.

But fish always are hiding somewhere.

Look a little harder and you will note that more of the banks are showing than usual. That the ponds, in fact, are down and dropping, with prospects of dropping even more.

The heat and an unusually severe drought are beginning to take an awful toll.

Millions and millions of fish in the shallower Forest Preserve lakes face the smothering prospect of ``summer kill,`` when high temperatures and low waters rob them of vital oxygen. Unless we get some hefty rains soon, some excellent game fish will die.

That is the fear of Dave McGinty, chief fish biologist for the forest preserves, who says he has ``never seen things this dry since I came here 15 years ago.``

And that includes the summer when millions of fish died a decade ago.

``It`s really getting bad,`` McGinty said after a tour of several Palos Woods area lakes. ``It`s already affecting the trees that require a lot of water, the apple trees and the oaks. You can see them showing signs of stress. ``I went by 30 marshes today. Most of them are bone dry.``

McGinty said the forest preserves have received about one-third their usual supply of rainfall. He expects that shallow ponds of 12 feet or less now have no oxygen at all in the bottom five or six feet of water.

That explains why so many bottom-feeding catfish are being caught on bass and walleye baits near the top. They no longer can exist on the bottom.

McGinty outlined a complex chain of biological events that occurs in heat and stagnant water. The high temperatures kill aquatic weeds that normally produce oxygen. These weeds decompose, using the remaining oxygen. In time, the minnows die, adding to the oxygen debt. Then the game fish go.

``The problem is that we still are facing our two hottest and driest months,`` McGinty said. ``And right now our water temperatures are in the upper 70s.``

The worst scenario calls for two or three days of heavy overcast, when water plants are incapable of producing oxygen because of lack of sunlight. They, of course, continue to consume a lake`s oxygen reserves at night, when their metabolic processes reverse and they produce carbon dioxide.

After two or three days, they can deplete a lake`s oxygen quickly. Then they die off.

The next sight is gasping fish on the surface.

The first fish to succumb are the larger bass, followed by choice channel cats. Then go the larger bluegills and crappies. Next are the white bass, then small panfish, then large carp, then bullheads, northern pike, tiny panfish and finally the small carp.

When the process starts, it moves quickly, McGinty said. Stressed fish in high temperatures have a higher metabolic rate. They need a lot more food and oxygen. If the supply is inadequate, they are stressed even more.

It`s too late now for aerators, McGinty said. They merely would mix oxygen-rich waters on top with oxygen-depleted waters on the bottom, thus thinning oxygen throughout the system. ``The time to install aerators is in the spring, before you have problems,`` he added.

Besides, McGinty said, any aerators he might leave in the forest preserves probably would be stolen.

He is chiefly concerned about the older and shallower glacial lakes on the southwest area, which have some of Cook County`s better fish populations. Sloughs like Saganashkee, Belly Deep and Horsetail and lakes like Tampier and Papoose are most susceptible.

``I`m not too worried about the north side lakes like Axehead, Belleau, Big Ben, Beck, Busse and Powder Horn,`` McGinty said. ``They are deep enough at 22 to 30 feet.`` So may be Maple Lake to the southwest.

McGinty is hoping for a gully-washer. ``A one-inch rain wouldn`t even faze the problem,`` he said. ``We need three or four inches at least. We need an inch to soak the ground, an inch to fill some of these smaller ponds and wetlands and another inch to get things flowing again.

``For example, we`d have to get Joe`s Pond, Tuma Lake, Belly Deep and all the Cranberry Slough marshes to overfill with water and pour into Crooked Creek so Saganashkee can get full again.

``We`re not talking about an inch. We had one inch the other day, and the ground was so hard it didn`t even soak in.``

McGinty warned that problems extend beyond the local forests.

``Take any of these dry creeks that have some pollution that normally is diluted,`` he said. ``Without runoff, all you get is discharge. That could raise hell on a lot of streams, especially the Des Plaines River.``

That would be a tragedy with the turbid Des Plaines now boasting gamefish, including largemouth bass.